Lifting appliance



Jan. 13, 1959 J. VILLARS LIFTING APPLIANCE 3 Sheets-Sheet 1 Filed July12, 1955 Jan. 13, 1959 J. VILLARS LIFTING APPLIANCE 3 Sheets-Sheet 2Filed July 12, 1955 JUL/O 1441 9/95 3 4% 7 CZZ- W/ Jan. 13, 1959 J.VILLARS LIFTING APPLIANCE 3 Sheets-Sheet 3 Filed July 12, 1955 ofappliance presents .several drawbacks.

goes down.

,descending, of the platform .duringthe lifting of said platform.

,r s truction of .the ,pqsition.

2 Claims. (Cl. 187-17) Lifting appliances are known for instance torender easier the loading of packages on lorries. This .kind ofappliance comprises generally a motoractuating a platform carried by amovable frame. Said frame is guided vertically by means of guidingmembers fastened on the one hand on the sides of said frame and on theother hand on the walls of a pit entirely closed said platform when thisplatform is in its lower position. Said kind Particularly the cost isrelatively high as the driving motor of the platform must be housed inan excavation especially made for it. Further, the Walls of the pit mustbe very solid in order to obviate any deformation Besides, this kind ofappliance comprises generally a masssuspended by a flexible memberconnected niemanner that said mass will be lifted when the platforrnWhen the platform goes up, said rnass lightens the load on the drivingmotor. .However, generally the weight of said mass does not exceed theweight of -the movable frame of the platform, that is to say. that thisweightis limited to the counterbalancing. of said platf rm,.in order to:obv iateth c nsider b e osts o am s -of. s ve lton The presentinvention has for g n object a lifting appliance comprising a platformcarried by a movable frame actuated by,a,motor,and which .is/characterized by the fact that itcomprises an auxiliary motor whichconstitutes an accumulator of energy storingenergy during the Theannexeddrawing shows schematically and by way tofsexampletwo forms ofconstructionof the hlifting. ap-

pliance object of the invention.

,-Fig. lQis, a perspective view of the first form, ofconappliance, theplatfor nmeingimitsdpwer Fig. 2 is a perspective view, the platformbeing in its lifted position, certain parts being cut away for clarity.

Fig. 3 is a cross section.

Fig. 3a is a fragmentary horizontal sectional view.

Fig. 4 is a view of a detail.

Figs. 5 and 6 are partial side and plan views of a modified form ofconstruction of the auxiliary motor.

According to Figs. 1 to 4 of the attached drawingthe appliance comprisesa platform 1 carried by a movable frame 2 having the general shape of acage. The four side faces of said frame are covered with sides 3. Themovable frame 2 is positionable within a pit 4 and is carried by meansof four flexible carrying members 5. Said members 5 are constituted bycables, one extremity of each of which is fastened to a central windingdrum 6, whilst the other extremity of each cable is fastened to thelower extremity of four uprights of the movable frame. Said carryingmembers pass over sheaves 8 rotating free on axes 9 rigidly fastened 0nthe upper exof the guiding members of the movable framecarrying theplatform.

and reta sa {e United States Pateht Ofiice Patent 13 1 59 tremities offour posts 10 fastened on the bottom 11 of the pit and located in thefour corners of said pit 4.

The drum 6 is driven by a vertical driving shaft 12 connected by areducing gear, housed in a casing 13, to the shaft of an electric motor14. Said shaft 12 coniprises a prolongation 15 which constitutes theshaft or an auxiliary motor .16. Said motor 16 comprises springs woundup on themselves and one of the extremities of each of which is fastenedto the shaft 15 whilst their other extremities stay against centralcolumns 17 fastened on the bottom of the pit and carrying the casing 13of the reducing gear. Distance pieces 18 connect rigidly the upperextremity of each post 10 to the casing 13 andto the columns 17. Saiddistance pieces constitute withthe posts and the columns an internalfixed frame.

When the platform is in its upper position (Fig. 2) its top is locatedfor instance at the level of the deck of truck (Fig. 2).

When the electric motor 14 is energized by lowering of a control memberM of a control casing C, the user causesthe lowering of the platform.The movable frame enters inside the pit. During said lowering stroke ofthe platform, the electric motor 14 winds up the springs andconsequently winds up the auxiliary motor. When the top of the platformreaches the level of the ground, an abutment 19 carried by themovableframe actuates the control member 20 of an end stroke circuit breaker 21circuit breaker 24.

The tests efi ectuated, have shown i that the auxiliary motor 16 causesalarge reduction in the power of the electric motor 14 which isnoimallynecessary to raise a given load, corresponding to the load for which theplatform is calculated, to a given height in a given time. Saidauxiliarymotor, wound up by the main motor and partly bythe load carriedby the platform during the lowering of said platform, constitutes infact an accumulator of energy. The energy accumulated by this auxiliarymotor is used to lift a part of carry. 1

The mechanical connection between the shaft of the motor 14- and thewinding drums 6, comprises a worm 26 meshing with a worm wheel 25. Thepitch bf saidworm is chosen in such a manner. as to realise anirreversible transmission, that is to say that the worm wheel subjectedby the intermediary of the cables, to the action of the weight of theplatform and of the load carried by said platform, may not in any casecause a rotation of said worm.

An advantage of the described appliance is that the shaftlS of theauxiliary motor carries the multiple winding drum 6. It follows that themembers of the reducing gear 13 do not carry a great part of the loadcarried by the platform. Consequently, the wear of the members of thereducing gear is far less than in the known appliances and their life isincreased.

The horizontality of the platform is ensured by the carrying cables,even if the load is located unsymmetrically on the platform. Each post10 carries further a guiding member 27 cooperating with guidesconstituted by the uprights forming the corners of the frame.

From the foregoing it results that the pit necessary for the housing ofthe platform and of its movable frame,

the load which the piatform may built and made 1n order to allow thefastening of such guiding members. Said walls may not be absolutelyvertical nor absolutely plane, without hindering thefgood working of theappliance. Besides, the total volu'm'efdf the pit necessary to house thedescribed appliance is approximately equal tothe volume of the movableframe of the platform. On the other hand, in the known appliances, thevolume of the pit is far greater (two to three times) than the volume'ofthe movable frame of the platform, that is to say than the volume whichmust be moved. 1

The energy accumulator constituted here by a spiral spring motormechanically connected to the winding drum, may be substituted by anyother kind of spring motor, such as a twisting spring for instance. Thefour carrying cables may be substituted by a carrying and pulling cableattached on the one hand to the lower part of an upright and on theother hand to the winding drum, and by three funicular cables of aconstant length. One of the extremities of each of said three cables maybe attached to the foot of one of the columns and the other extremityofeach of the funicular cable, may be fastened to the extremity of oneof the three other uprights, after having passed over a rotatable guidecarried by the corresponding column. Such a disposition of pullingcarrying cables and of funicular carrying cables, is already known andused for instance in lifting appliances for touring cars and describedfor instance in the U. S. Patent No. 2,640,562.

Figs. 5 and 6 show partially a modified form of construction of anappliance according to the invention. The auxiliary motor 16 comprises acylinder 28 in which slides a piston 29. Said piston is mechanicallyconnected, by means of a toothed rack 30 and a pinion 31, to the shaft15. A duct 32 connects said cylinder to a bottle partially filled withliquid.

When the platform goes down, the piston penetrates inside the cylinderand compresses the gas contained in the upper part of said bottle 33.Said gas, perfectly elastic, restores the stored energy during the nextactuating upwards displacement of the platform.

Two forms of execution of an appliance object of the invention have beendescribed here by way of examples, :but it goes without saying thatseveral variants may be realised, adapted to the several requirementsprescribed in each particular case.

From the foregoing one may easily see that the appli ance object of theinvention is of a cost which is much cheaper than the cost of anappliance of a known kind.

Besides, the consummation of electric energy and thus the power of themotor which must be foreseen, is much less than in the known appliances,for the main electric motor is of a power approximately equal to half ofthe power which would be necessary, in the absence of an auxiliarymotor, in order to raise a given load to a given height in a given time.This particular point represents also a great advantage of the describedappliance.

I claim:

1. In a lifting appliance, a platform having frame means dependingtherefrom, said platform and frame means being adapted to be raised fromand lowered into a pit, sheaves positioned in the upper part of said pitadjacent said frame means, motive means, transmission means drivinglyconnected with said motive means, means supporting said motive means andsaid transmission means in said pit, said transmission means having acentral vertical output shaft having a drum thereon, cables connected tosaid drum extending over said sheaves and attached to the lower ends ofsaid frame means, and an energy accumulator in said pit, a'downwardprolongation of said output shaft, said accumulator being operativelyconnected to said prolongation of said output shaft of said transmissionmeans; whereby said motion means, transmission means, support means,drum, andenergy accumulator have a combined vertical height no greaterthan the height of said frame means.

2. In a lifting appliance, a platform having frame means dependingtherefrom, said platform and frame means being adapted to be raised fromand lowered into a pit, sheaves positioned in the upper part of said pitadjacent said frame means, motive means, transmission means drivinglyconnected with said motive means, meansv supporting said motive meansand said transmission means in said pit, said transmission means havingan out-- put shaft having a drumthereon, cables connected to said drumextending over said sheaves and attached to the lower ends of said framemeans and an energy accumulator in said pit, a downward prolongation ofsaid output shaft of said transmission means, said energy accumulatorcomprising spring means having one end thereof attached to said downwardprolongation of said output shaft and the other end anchored to a fixedobject, whereby said motive means, transmission means, support means,drum and spring means of said-energy accumulator have a combinedvertical height no greater than the height of said frame means.

References Cited in the file of this patent UNITED STATES PATENTS269,994 Bailey Ian. 2, 1883 544,780 Winters Aug. 20, 1895 968,501 TurnerAug. 23, 1910 1,710,552 Rood Apr. 23, 1929 1,849,348 Davis Mar. 15, 19322,250,965 Pritz July 29, 1941 2,269,786 Rose Jan. 13, 1942 2,517,318Jeffers Aug. 1, 1950

